JP2016172085A - Healing absorbent dressing and use of the same for chronic wound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a healing absorbent dressing, and use of the same for a chronic wound.SOLUTION: One of a subject of the present invention is a coating material having a core/shell-type heat-adhesive non-absorbent composite fiber having a core comprising polyester (polyethylene terephthalate, PET) and a shell comprising polyethylene, an absorbent non-woven fabric compress comprising a mixture with a core/shell-type super-absorbent composite fiber having the core comprising polyacrylonitrile and the shell comprising polyacrylate, and a mesh cloth partially covering the surface coming into contact with the wound of the compress and made from a hydrocolloid elastomeric material, as essential components. This coating material is especially used for promoting healing of a chronic wound by optimizing debridement.SELECTED DRAWING: None

Description

The present invention relates to a coating material having an absorbent nonwoven fabric compressing fabric and an elastomer contact layer containing a hydrocolloid. The dressing is very effective for the treatment of wounds where acceleration of healing is desired. This makes it possible to manage the presence of fibrin in addition to the exudate from the wound without complementation by debridement methods such as surgery and enzymes.

The wound heals spontaneously in three consecutive stages. Each stage is characterized by specific cellular activity and consists of a debridement phase, a growth (granulation) phase and an epithelialization phase. During the healing process, fluid or viscous exudates ooze out of the wound and must be absorbed by the dressing.

If the degree of trauma is significant or if the patient suffers from a similar disease such as venous disease or diabetes, the natural debridement ability of the wound may not be sufficient. In such a case, it is recognized that the debridement period is considerably prolonged, resulting in a chronic wound that is difficult to treat, such as a lower leg ulcer.

In wounds where the natural debridement process is insufficient, fibrin tissue needs to be removed without interfering with the growth phase. This removal of fibrin tissue is generally referred to as an “assisted debridement” relative to the natural debridement.

Depending on the method used, the auxiliary debridement is called a mechanical or surgical debridement, an enzymatic debridement, a self-melting debridement, or a biological debridement.

Surgical or mechanical debridement can quickly remove fibrin tissue using a scalpel, tweezers, scissors or block curette, or by high pressure water jet or laser ablation using high performance instruments. It is a simple method. This method is performed in the patient's bed and surgical environment depending on the extent of the wound. However, this method is often painful, sometimes bleeds, and sometimes even causes massive bleeding. This gives the patient a psychological shock. Also, it is usually necessary to administer an analgesic in advance, which increases the treatment period.

The self-melting debridement is to place an absorbent covering material mainly composed of a special gelled fiber on a wound.

Generally, the coating material used for debridement is a needle punched nonwoven fabric (a product of this type is sold as Aquacel®) made of gelled fibers of alginate or carboxymethylcellulose. Such a covering material has a problem that the cohesiveness is insufficient and it collapses as the exudate is absorbed, and the debris remains on the wound and cannot be removed as a unit. In order to solve this problem, it has been proposed to arrange a perforated adhesive layer on the surface of the nonwoven fabric so as to hold the fibers separated from the nonwoven fabric while ensuring a flow path for the exudate (Patent Document 1). Proposed hole diameters are on the order of 5-8 mm.

Patent Document 2 proposes to use a nonwoven fabric of superabsorbent fibers in which fibers are needle-punched and sufficiently spaced so that exudates can still pass even if they swell. ing. The spacing between the fibers greatly reduces the cohesiveness of the nonwoven fabric, so it is necessary to prevent the fibers separated from the nonwoven fabric from contaminating the wound. Therefore, in Patent Document 3, a loop in which intersecting portions are joined is formed by fiberization, and the yarn of the thermoplastic material is arranged on the nonwoven fabric. In order to ensure quick initial absorption of exudate by the absorbent layer, the basis weight of the yarn should be less than 100 g / m ² . Specifically, it is indispensable to insert an intermediate layer between the wound and the nonwoven fabric so as not to reduce the absorption rate and absorption capacity of the nonwoven fabric. Similarly, this interlayer should not adversely affect the self-melting debridement ability of such a coating.

These dressings are far from allowing optimal debridement. They are often used in combination with a mechanical debridement man who has to take action to give the patient a mental shock or pain. Therefore, it would be beneficial to reduce or eliminate the dependence on the mechanical debridement.

Thus, a dressing for the treatment of wounds, in particular chronic wounds, in spite of the intermediate layer between the wound and the non-woven fabric, the exudate absorption and absorption rate of the dressing and the self-melting debating It would be desirable to provide a dressing that can optimally remove fibrin so as not to adversely affect the Reedman ability, and preferably to reduce or eliminate reliance on surgical procedures. It is also desirable for the dressing to be able to promote healing of areas where there is no fibrin in the wound and not adversely affect tissue reconstruction upon removal. Finally, it is desirable that this dressing is highly cohesive and does not cause pain when removed.

International Publication No. 2002/03898 International Publication No. 2007/025546 International Publication No. 2007/025544

The applicant has developed a coating material that satisfies the above requirements. This covering material is comprised with the superabsorbent nonwoven fabric in which the part facing a wound is covered with the specific contact layer. This layer ensures that the fibrin can be removed while at the same time removing the used dressing without pain. Quite unexpectedly, even when this specific layer was inserted between the wound and the nonwoven fabric compress, the exudate absorption ability and the self-melting debridement ability of the dressing were not reduced. Furthermore, the applicant has confirmed that when removing the dressing, the fibrin sticks to the dressing and can be removed as a whole.

Accordingly, the present invention provides for the first time a dressing that simultaneously promotes self-melting debridement and granulation of a wound and that can treat the entire area of the wound even though it is not necessarily at the same healing stage. By doing so, it is possible to optimize the healing of wounds, in particular chronic wounds.

Furthermore, the dressing of the present invention can absorb exudate very quickly while keeping the wound in a moist environment. When contacted with the exudate, the contact layer gels, and the nonwoven fabric compressing fabric absorbs the exudate. The moist environment formed on the wound surface can promote healing.

Finally, the coating of the present invention is highly cohesive and will not tear when removed.

In the dressing structure of the present invention constituted by an aggregate of a nonwoven fabric of superabsorbent fibers and a layer in contact with the wound, the exudate can be reliably and quickly absorbed over a long period of time. It is desirable to prevent maceration of the skin around the wound and lesion.

The purpose of the present invention is a highly cohesive coating material composed of a specific nonwoven fabric and a specific contact layer, and reliably absorbs exudate without adversely affecting the self-melting debridement ability of the coating material. At the same time, preferably to facilitate removal of fibrin in bulk, at the same time to provide a dressing that can be removed without pain, to maintain the integrity of the proliferating tissue and promote its growth, It is to ensure that the exudate is absorbed quickly and consistently during use so as not to cause maceration problems.

The specific contact layer is made of an elastomer composition in order to maintain flexibility and conform to the shape of the body.

The dressing of the present invention is painless when removed. Further, since the contact layer is gelled, it does not adhere to the wound and forms a good moist environment, so that the covering material is effective for healing in a region where no fibrin is present. The nonwoven fabric continues to absorb fibrin and exudate because the size of the contact layer opening does not decrease while absorbing exudate.

Thus, the subject of the present invention is
a. An absorbent non-woven compress fabric comprising a superabsorbent fiber, preferably a mixture of superabsorbent composite fiber and heat-adhesive non-absorbent fiber, wherein the entire fiber is thermally bonded;
b. A dressing having a contact layer partially covering the surface of the compressing fabric in contact with the wound, wherein the layer has an opening through which wound exudate can pass; 500 g / m ^2, the layer is a coating material comprising an elastomer substrate and a hydrocolloid composition, the hydrocolloid content being 2% to 20% by weight of the composition .

According to a preferred embodiment of the present invention, the covering material is
a. Core / shell type heat having a core / shell type superabsorbent composite fiber having a core made of polyacrylonitrile and a shell made of polyacrylate, a core made of polyester (polyethylene terephthalate, PET) and a shell made of polyethylene An absorbent non-woven compress fabric comprising a mixture of adhesive non-absorbent fibers, wherein the entire fiber is thermally bonded;
b. A contact layer that partially covers the surface of the compressing fabric that contacts the wound, the layer having an opening through which exudate can pass, and the basis weight of the layer is in the range of 150 to 200 g / m ² The layer comprises a composition comprising an elastomeric substrate and a hydrocolloid, wherein the hydrocolloid comprises 2 wt% to 20 wt% of the total weight of the composition, and the layer is exposed to wound exudate The surface of the compressing fabric facing the wound is covered by 55% to 65%.

The covering material which concerns on this invention contains the absorption layer which consists of a nonwoven fabric obtained from the mixture of a superabsorbent fiber and a non-absorbent fiber.

In the present specification, the expression “superabsorbent” means a fiber having a very high liquid absorption capacity, preferably a liquid absorption capacity of 10 g / g or more of water (or saline such as physiological serum), more preferably water. It should be understood that it refers to a fiber having a liquid absorbency greater than 20 g / g, more preferably a liquid absorbency greater than 30 g / g water.

According to the invention, the superabsorbent fibers are preferably made of two different materials. These materials may be arranged in parallel, but preferably take a core / shell structure.

The first material forming the exterior of the fiber, preferably the shell, must be capable of forming a gel with the wound exudate, advantageously one or more cross-linked and / or partially cross-linked polymers, In particular, it is composed of an acrylic acid polymer and / or an acrylate polymer, especially a sodium acrylate or ammonium polymer.

The second component that preferably forms the core of the superabsorbent fiber is not gelled and has an affinity for the first material so that the stability of the fiber after the first material forms a gel can be ensured. It is preferable. The polymer may be formed of any kind of polymer as long as the polymer is stable in an aqueous medium and has an affinity for the shell material so that a stable conjugate fiber can be obtained.

This second material advantageously consists of polyacrylonitrile.

Advantageously, the size of the superabsorbent fiber is 2-6 dtex.

Superabsorbent fibers that can be used in the present invention are sold, for example, by Toyobo Co., Ltd. under the trade name LANSEAL (registered trademark) F.

Non-absorbent fibers reinforce and stabilize the three-dimensional structure of the nonwoven fabric by forming a reinforcing structure by bonding the fibers together and / or by bonding the fibers to the superabsorbent fibers. Is a heat-bondable fiber.

The second fiber may be made of one kind of thermoplastic material such as low melting point polyethylene, polypropylene or polyester.

The second fiber is also advantageously made of two different materials arranged in parallel, preferably in a core / shell structure.

The length of the fiber may be about 10 to 100 mm, preferably about 25 to 75 mm.

In the present invention, a core / shell type heat-adhesive non-absorbable conjugate fiber having a core formed of polyester, particularly polyethylene terephthalate, and a shell formed of polyethylene is particularly preferable.

Usually, the nonwoven fabric forming the absorbent compress of the dressing of the present invention is obtained from a mixture containing more than 50% by weight, preferably more than 60% by weight of superabsorbent fibers.

20 / 80-80 / 20 may be sufficient as the weight ratio of the said absorptive fiber and the said heat bondable non-absorbable fiber, Preferably it is 60 / 40-80 / 20. Excellent results were obtained using a mixture containing 30% by weight of non-absorbent fibers and 70% by weight of superabsorbent fibers.

The non-woven fabric is usually obtained by heat-bonding a mixture of fibers or by needle-punching and heat-bonding.

In particular, the superabsorbent fibers can be oriented substantially perpendicular to the surface of the nonwoven fabric by the needle punching process. This fiber orientation can prevent the exudate absorbed by the dressing containing the nonwoven from spreading laterally, thus reducing the risk of maceration and resulting deterioration of the skin surrounding the lesion. Can be reduced.

The thermal bonding step can improve the tear resistance of the nonwoven fabric after absorption by forming a fixing point between the fibers of the nonwoven fabric. In order to remove the used coating material without tearing, it is necessary to enhance the cohesiveness of the nonwoven fabric.

Thickness 0.6～3Mm, preferably a thickness 2 mm, basis weight 40400 g / ^{m 2,} preferably combine the fibers in conditions basis weight 185 g / ^{m 2} approximately nonwoven is obtained.

The nonwoven fabric compressible cloth can be manufactured by the method described in Patent Document GB2401879.

The nonwoven fabric may contain various active substances, for example, substances having antibacterial activity, particularly silver salts such as silver sulfate, silver chloride, silver nitrate, silver sulfadiazine, quaternary ammonium, polyhexamethylene biguanide, chlorhexidine, and the like. Good. In addition, for example, substances that promote healing, such as growth factors and polysulfated oligosaccharides such as potassium salt of sucrose octasulfate, may be included.

Moreover, you may include the fiber which has antimicrobial property in the said nonwoven fabric. For example, such fibers may include metals (silver, copper, zinc) or other antimicrobial active agents. In the case of metals, such fibers can be produced in various ways: compounding the polymer into a polymer substrate during extrusion (PP, PET, PA) or in a spin finish during the spinning process. It can be obtained by applying a metal. The metal used for the preparation of such fibers may be in the form of a salt, zeolite, ceramic or nanoparticles.

The elastomer composition containing a hydrocolloid that can be used for producing the coating material according to the present invention includes an elastomer base material, preferably an elastomer base material in which the hydrocolloid is uniformly dispersed.

The use of the contact layer of the dressing of the present invention is advantageous because it does not adhere to the wound and does not cause any pain when the dressing is removed. Healing is promoted by holding a moist medium on the surface of the wound while preventing contact with an absorbent compress comprising exudate. By including a hydrocolloid, the elastomeric composition is hydrophilic and facilitates the vectorization of active agents that promote wound healing.

The composition includes one or more elastomers selected from poly (styrene / olefin / styrene) block polymers. The block copolymer used in the present invention is advantageously an ABA type triblock copolymer having two styrene thermoplastic end blocks A and an elastomer central block B which is an olefin. The block copolymer may be combined with an AB type diblock copolymer comprising a styrene thermoplastic block A and an elastomer block B which is an olefin. The olefin block B of these copolymers may be composed of an unsaturated olefin such as isoprene or butadiene, or may be composed of a saturated olefin such as ethylene / butylene or ethylene / propylene.

In the case of a mixture of ABA triblock copolymer and AB diblock copolymer, a prepared commercial mixture of ABA triblock copolymer and AB diblock copolymer can be used, or obtained respectively A mixture of any proportion determined in advance may be prepared from the two products.

Triblock copolymers having an unsaturated central block are well known to those skilled in the art. In particular, it is sold under the trade name KRATON (registered trademark) D by Kraton Polymers.

Examples of poly (styrene / isoprene / styrene) (abbreviated as SIS) copolymers include products sold under the trade name KRATON (registered trademark) D1107 or KRATON (registered trademark) D1119 BT, and the trade name VECTOR ( As a registered trademark, a product sold by Exxon Mobile Chemical (for example, a product sold under the trade name VECTOR (registered trademark) 4113) can be cited. An example of a poly (styrene / butadiene / styrene) copolymer is a product sold under the trade name KRATON® D1102.

An example of a commercially available mixture of an ABA triblock copolymer and an AB diblock copolymer, where B is isoprene, is the product sold under the trade name VECTOR® 4114 by Exxon Mobile Chemical.

All of these isoprene-based or butadiene-based copolymers usually have a styrene content of 10% to 52% by weight based on the total weight of the copolymer.

In the present invention, the poly (styrene / isoprene / styrene) (abbreviated as SIS) triblock copolymer has a styrene content of 14% by weight to 52% by weight based on the weight of the poly (SIS), preferably It is preferable to use 14% by weight to 30% by weight.

For the preparation of the composition according to the invention, it is preferred to use a triblock copolymer, in particular a product sold under the trade name KRATON® D1119 BT by Kraton Polymers.

Triblock copolymers having a saturated central block are also well known to those skilled in the art, for example the following are sold.
-Trade name KRATON (registered trademark) G, especially poly (styrene / ethylene / butylene / Styrene) (abbreviated as SEBS) block copolymer;
-Poly (styrene / ethylene / propylene / styrene) (abbreviated as SEPS) block copolymer sold by Kuraray Co., Ltd. under the trade name SEPTON (registered trademark).

An example of a commercially available mixture of triblock and diblock copolymers is the product sold by Kraton Polymers under the trade name KRATON® G1657, the olefin block being ethylene / butylene.

Examples of specific mixtures of triblock and diblock copolymers that can be prepared in the present invention include mixtures of:
SEBS triblocks, especially products sold under the trade name KRATON (registered trademark) G1651 by Kraton Polymers, etc .; and
Poly (styrene / olefin) diblock copolymers, especially poly (styrene / ethylene / propylene) sold under the trade name KRATON (registered trademark) G1702 by Kraton Polymers.

In the present invention, among SEBS or SEPS triblock copolymers, those having a styrene content of 25 wt% to 45 wt% based on the weight of the SEBS or SEPS are preferred. Preference is given to using triblock copolymers, in particular the products sold by Kraton Polymers under the trade names KRATON® G1651 and KRATON® G1654.

Usually, the elastomer is used in an appropriate amount depending on the saturation or unsaturation property of the olefin central block of the block copolymer. Therefore, in the case of a triblock copolymer having an unsaturated central block, it is used in an amount of about 10% to 30% by weight, preferably about 10% to 20% by weight, based on the total weight of the composition. In the case of a triblock copolymer having a saturated central block, it is used in an amount of about 3% to 10% by weight, preferably about 4% to 7% by weight, based on the total weight of the composition.

In the present specification, the expression “hydrocolloid” or “hydrocolloid particles” refers to any compound that is commonly used by those skilled in the art as having the ability to absorb water, physiological serum, wound exudates, and other aqueous liquids. I want you to understand.

Suitable hydrocolloids include, for example, pectin, alginate, natural vegetable rubber (particularly Karaya gum, etc.), cellulose derivatives such as carboxymethylcellulose, and alkali metal salts thereof (sodium or calcium salts, etc.), as well as, for example, trade names from BASF LUQUASORB (registered trademark) 1003, an acrylate-based synthetic polymer known as "superabsorbent", such as a product sold under the trade name SALCARE (registered trademark) SC91 by Ciba Specialty Chemicals, and And mixtures of these compounds.

Some of the superabsorbents referred to as “microcolloids” have a particle size of less than 10 micrometers and can of course be used in the preparation of the composition.

A preferred hydrocolloid in the present invention is an alkali metal salt of carboxymethyl cellulose, particularly sodium carboxymethyl cellulose (CMC). The size of the hydrocolloid particles is, for example, 50 to 100 microns, particularly about 80 microns.

The amount of hydrocolloid blended in the elastomer composition is advantageously about 2% to 20% by weight, preferably about 5% to 18% by weight, based on the total weight of the elastomer composition. More preferably, it is about 8 to 18% by weight, and further preferably about 12 to 16% by weight. If the amount of hydrocolloid introduced into the perforated contact layer is too large, the absorbent capacity of the nonwoven fabric mainly composed of superabsorbent fibers is reduced when a gel is formed. In fact, the high absorptivity of the hydrocolloid can cause the contact layer to swell, resulting in plugging of the mesh holes. The absorbent nonwoven can no longer absorb the exudate directly and absorbs the exudate contained in the hydrocolloid absorption layer. As a result, the absorption capacity of the covering material is lowered, and the problem of maceration occurs.

The composition comprises one or more elastomers selected from poly (styrene / olefin / styrene) block polymers in combination with one or more plasticizing compounds and optionally one or more antioxidants. Including.

The elastomer composition of the coating material of the present invention contains one (or more) plasticizing compound in order to improve its stretchability, flexibility, extrusion moldability or processability.

They are preferably liquid compounds having an affinity for the olefin central block of the block copolymer used.

Among the plasticizing compounds that can be used for the above purpose, mineral oil for plasticization is particularly mentioned regardless of the nature of the central block. For example, in addition to polybutene such as products sold under the trade name NAPVIS (registered trademark) 10 by BP Chemicals, phthalic acid derivatives such as dioctyl phthalate and dioctyl adipate are used when the central block is unsaturated. Can be mentioned.

Further, for example, products sold by Total under the trade name GEMSEAL (registered trademark), particularly liquid mixtures of saturated hydrocarbons such as GEMSEAL (registered trademark) 60, which is an isoparaffinic mixture derived from a fully hydrogenated petroleum fraction. The synthesized product can also be used. In the case of a triblock copolymer having a saturated central block, these products are preferably used.

In the present invention, it is preferable to use a plasticizing oil, in particular, a mineral oil composed of paraffinic, naphthenic or aromatic compounds, or a mixture of various ratios thereof.

Among the particularly preferred plasticizing oils, the following can be mentioned.
-Products sold by Shell under the trade names ONDINA (registered trademark) and RISELLA (registered trademark) consisting of a mixture mainly composed of naphthenic and paraffinic compounds;
A product sold under the trade name CATENEX (registered trademark) consisting of a mixture mainly composed of naphthenic, aromatic and paraffinic compounds.

It is particularly preferred to use a plasticizing mineral oil selected from the products sold under the trade name ONDINA® 963 and the trade name ONDINA® 919.

These plasticizing compounds may be used in an amount of about 20% to 65% by weight, preferably about 30% to 50% by weight, based on the total weight of the hydrocolloid elastomer composition.

According to one embodiment, the composition is sticky and does not adhere to the wound but adheres to the skin. The above composition contains one or more compounds called “tackifiers” such as compounds usually used by those skilled in the art for the preparation of elastomeric pressure sensitive adhesives. For a detailed description of these products, see Donata Satas, “Handbook of Pressure Sensitive Technology”, 3rd edition, 1999, pages 346-398.

In the present invention, it is preferable to use a contact layer having a low adhesive strength. Because of the low adhesive strength, the nurse can apply supporting members such as support bandages using both hands once the dressing is applied, and can also reposition the dressing without damaging healthy tissue. Because it can. Such a covering material is referred to as slightly sticky.

Usually, one (or more) tackifier can be added to the elastomer substrate at a ratio of about 1% to 50% by weight of the total weight of the hydrocolloid elastomer composition. This ratio is determined according to the properties and relative ratios of the other components of the hydrocolloid elastomer composition so that the desired fine adhesion of the coating material can be obtained.

The tackifier is preferably 10% to 45% by weight, more preferably 15% to 40% by weight of the total weight of the hydrocolloid elastomer composition.

The tackifier that can be used in the present invention can be selected from tackifier resins, low molecular weight polyisobutylenes or mixtures thereof.

Among the tackifying resins that can be used in the present invention, a modified terpene or polyterpene resin, a rosin resin, a hydrocarbon resin, a mixture of cyclic, aromatic and aliphatic resins, or a mixture of these resins.

Such materials are commercially available and examples include the following.
-Hydrogenated polycyclopentadiene resin sold under the trade name ARKON (registered trademark) P by Arakawa Chemical Industries, Ltd .;
-Products sold under the trade name ESCOREZ (registered trademark) by Exxon Chemical, in particular 5000 series hydrogenated resins;
・ Products sold under the trade name WINGTACK (registered trademark) by Goodyear, in particular, WINGTACK (registered trademark) 86, which is a synthetic resin made of a C5 / C9 copolymer, or WINGTACK (registered), which is a synthetic polyterpene resin Trademark) 10;
A product sold by Hercules under the trade name KRISTALEX (registered trademark), in particular KRISTALEX (registered trademark) 3085, which is an α-methylstyrene resin.

Usually, it is preferred to use a hydrogenated resin in combination with a triblock copolymer having a saturated central block, in order to prevent problems with coloring and stability of the unsaturated resin. This is because the affinity between the hydrogenated resin and the triblock copolymer is much higher than that of the WINGTACK type unsaturated resin that is basically used in combination with a triblock copolymer having an unsaturated central block. Because.

Among these resins, ESCOREZ (registered trademark) 5000 series resins are preferably used, and ESCOREZ (registered trademark) 5380 resin is particularly preferable.

The tackifying resin may be used alone or as a mixture with other tackifying substances. The tackifying resin is preferably used in a proportion of 10% to 50% by weight, more preferably 15% to 40% by weight, based on the total weight of the composition.

Among low molecular weight polyisobutylenes that can be used as a tackifier, for example, they are sold by BASF under the trade names OPPANOL (registered trademark), in particular, trade names OPPANOL (registered trademark) B12 and OPPANOL (registered trademark) B15. Examples thereof include polyisobutylene having a molecular weight of about 40,000 to 80,000 daltons, such as products and products sold by Exxon Chemical under the trade name Vistanex, particularly LM-MH grade.

These polyisobutylenes may be used alone or as a mixture with other tackifiers in combination with a triblock copolymer having an unsaturated central block. The content of the polyisobutylene varies, but in this example, it is 5 to 30% by weight, particularly 8 to 15% by weight, based on the total weight of the composition.

The composition that can be used for producing the coating material of the present invention may further contain one or more antioxidants.

In the present specification, the expression “antioxidant” is used to ensure the stability of the compounds used in the compounding of the adhesive material, particularly the tackifier resin and the block copolymer, against oxygen, heat, ozone and ultraviolet radiation. It should be understood that it refers to compounds commonly used by those skilled in the art.

Examples of suitable antioxidants include the following.
-Phenol antioxidants, especially products sold by Ciba Specialty Chemicals under the trade names IRGANOX (registered trademark) 1010, IRGANOX (registered trademark) 565 and IRGANOX (registered trademark) 1076;
-Sulfur-containing antioxidants, particularly zinc dibutyldithiocarbamate sold by AKZO under the trade name PERKACIT (registered trademark) ZDBC.

These antioxidants can be used in an amount of about 0.05% to 1% by weight, preferably 0.1% to 0.5% by weight, based on the total weight of the elastomer composition.

In the present invention, it is preferable to use IRGANOX (registered trademark), particularly IRGANOX (registered trademark) 1010.

Various compounds, in particular, adjuvants or active agents that are usually used in the field of wound treatment or pharmacology, may be further added to the elastomer composition.

The composition may comprise an active ingredient that plays a favorable role in wound treatment. These active ingredients can in particular act during the debridement and / or granulation stages of the wound to induce or promote healing. It has been confirmed that the contact layer in the present invention is excellent as a mediator for releasing the active ingredient, especially thanks to the presence of hydrocolloid.

The active agent can be used in an amount of about 0.01% to 20% by weight, preferably 1% to 15% by weight, especially 2% to 10% by weight, based on the total weight of the composition. .

Among the effective substances that can be used in the present invention, bactericides or bacteriostatic agents, healing accelerators, analgesics, or anti-inflammatory agents can be mentioned as examples.

Adjuvants include dyes, fillers, odor absorbers or odor scavengers, UV screening agents, pH adjusters, microcapsules or microspheres that may contain active agents as necessary, and coating materials with an oily appearance. Or polymer or surfactant to optimize gelation rate, wettability or release of the active agent in the composition.

If the composition contains an unsaturated polymer, the copolymer AcResin (R) may be used to improve gelation, gelation rate, wettability, or as needed in the composition The surfactant MONTANOX® 80 or the polymer SEPINOV® EMT10 (both sold by SEPPIC) may be used to optimize the release of the formulated active agent.

In the preparation of a coating material using a composition mainly composed of an elastomer copolymer having a saturated central block, it is preferable to use a composition containing the following with respect to a total weight of 100% by weight.
0.05% to 1% by weight of antioxidant;
10 wt% to 50 wt% tackifying resin;
2% to 20% by weight of hydrocolloid, especially sodium carboxymethylcellulose, preferably 12% to 16% by weight;
20% to 65% by weight of plasticizer, especially plasticizing mineral oil;
3% to 10% by weight of poly (styrene / ethylene / butylene / styrene) or poly (styrene / ethylene / propylene / styrene) triblock polymer;
1% by weight to 15% by weight of a copolymer composed of 2-methyl-2-[(1-oxo-2-propenyl) amino] -1-propanesulfonate and 2-hydroxyethyl ester of propenoic acid.

In the preparation of a coating material using a composition mainly composed of an elastomer copolymer having a saturated central block, it is preferable to use a composition containing the following with respect to a total weight of 100% by weight.
0.05% to 1% by weight of antioxidant;
10 wt% to 50 wt% tackifying resin;
2% to 20% by weight of hydrocolloid, especially sodium carboxymethylcellulose, preferably 12% to 16% by weight;
20% to 65% by weight of plasticizer, in particular mineral oil;
3% to 10% by weight of poly (styrene / ethylene / butylene / styrene) or poly (styrene / ethylene / propylene / styrene) triblock polymer.

The other composition mainly composed of an elastomer copolymer having a saturated central block may contain the following with respect to a total weight of 100% by weight.
0.05% to 1% by weight of antioxidant;
2% to 20% by weight of hydrocolloid, especially sodium carboxymethylcellulose, preferably 12% to 16% by weight;
20% to 65% by weight of plasticizer, in particular mineral oil;
3% to 25% by weight of poly (styrene / ethylene / butylene / styrene) or poly (styrene / ethylene / propylene / styrene) triblock polymer.

In the preparation of a coating material using a composition mainly composed of an elastomer copolymer having an unsaturated central block, it is preferable to use a composition containing the following with respect to a total weight of 100% by weight.
0.05% to 1% by weight of antioxidant;
10 wt% to 60 wt% tackifying resin;
2% to 20% by weight of hydrocolloid, especially sodium carboxymethylcellulose, preferably 12% to 16% by weight;
10% to 65% by weight of plasticizer, in particular mineral oil or phthalic acid derivative;
5% to 25% by weight of poly (styrene / butadiene / styrene) or poly (styrene / isoprene / styrene) triblock polymer;
1% by weight to 15% by weight of a copolymer composed of 2-methyl-2-[(1-oxo-2-propenyl) amino] -1-propanesulfonate and 2-hydroxyethyl ester of propenoic acid.

One particularly preferred composition comprises the following for a total weight of 100% by weight.
0.05% to 1% by weight of antioxidant;
30 wt% to 40 wt% tackifying resin;
2% to 20% by weight of hydrocolloid, especially sodium carboxymethylcellulose, preferably 12% to 16% by weight;
35% to 45% by weight of plasticizer, especially plasticizing mineral oil;
4% to 6% by weight of poly (styrene / ethylene / butylene / styrene) or poly (styrene / ethylene / propylene / styrene) triblock polymer;
2% by weight to 8% by weight of a copolymer comprising 2-methyl-2-[(1-oxo-2-propenyl) amino] -1-propanesulfonate and 2-hydroxyethyl ester of propenoic acid.

The above-mentioned composition can be prepared by mixing various components at a high temperature of 90 ° C. to 160 ° C., preferably 110 ° C. to 140 ° C., according to a hot melt method well known to those skilled in the art. Preferably, the hydrocolloid elastomer composition is deposited by dip coating the etched cylinder in a premixed composition. The composition thus molded is then transferred to the nonwoven by the cylinder.

Practically, the elastomer composition is protected by covering at least the surface in contact with the wound with a protective layer or a protective film. The protective layer or protective film can be removed before using the covering material.

The contact layer containing the elastomer composition has various forms such as a perforated sheet made of the elastomer composition, a mesh-like cloth obtained by extrusion molding or molding the composition, or a knitted fabric coated with the elastomer composition. I can take it. In order to obtain the desired adhesive strength, a flat contact layer is preferred.

The size of the opening of the contact layer is preferably selected so that the average diameter or average length is 1 to 3 mm, preferably 1 to 2 mm, and particularly about 1.5 mm. The surface area of the opening is, for example, 0.5 to 10 mm ² , preferably 0.8 to ⁶ mm ² .

According to one embodiment, the contact layer does not cover more than 80% of its surface so that exudate can be optimally absorbed by the pressing cloth. Advantageously, the contact layer is configured to cover 50% to 80%, preferably 65% to 75% of the surface of the compression fabric facing the wound prior to exposure to wound exudate. is there.

Preferably the basis weight of the contact layer is in the range of 110~250g / ^{m 2,} more preferably in the range of 160~200g / ^{m 2,} for example 185 g / ^{m 2} approximately. Therefore, the applicant proposes a contact layer that has a large basis weight and covers the majority of the surface of the pressing fabric. Quite unexpectedly, this contact layer does not interfere with the speed and capacity of absorbing the exudate of the pressing fabric.

According to one embodiment, the contact layer is in the form of a mesh-like cloth made of yarn, the thickness measured in a plane parallel to the surface of the maximum area is 1 to 3 mm, and the interval is 1 to 3 mm. is there.

In one embodiment of the present invention, the basis weight of the pressing cloth and the basis weight of the contact layer are substantially the same. The difference in the basis weight between the two is, for example, less than 20% of the maximum value of the basis weight, more preferably less than 10%.

The size, shape and relative arrangement of the opening of the contact layer are selected so that the layer can sufficiently withstand deformations imposed during, for example, a high temperature release process when applied to a nonwoven fabric compress. . Further, the opening must have a sufficient size, and the compression cloth can absorb the exudate more rapidly than the hydrocolloid dispersed in the contact layer. Must be thin enough.

In one particular embodiment of the invention, the layer is
-It is in the form of a mesh-like cloth made of yarn, the thickness of the yarn measured in a plane parallel to the surface of the maximum area is 1 to 3 mm, and the interval of the yarn is 1 to 3 mm
-A basis weight is 170-200 g / m < ² >,
The hydrocolloid is contained in an amount of 12 to 16% by weight based on the weight of the composition forming the contact layer.

The features described above with respect to the present invention naturally apply to this particular embodiment as well. For example, the basis weight of the pressing cloth may be substantially the same as that of the contact layer.

As a method of covering the pressing cloth with the contact layer, it is preferable to perform a transfer process using an etched cylinder. After immersing the cylinder in the melted elastomer composition, the heat-uncooled mesh is released on the nonwoven fabric compress. This method is advantageous because solid hydrocolloid particles having a relatively large particle size can be introduced. Furthermore, the contact layer can be optimally adhered onto the pressing cloth by applying the composition which is not cooled by heat to the pressing cloth.

The invention is illustrated by the following examples.

Example 1:
Fabrication of non-woven fabric Weight ratio: 70% (super absorbent fiber) / 30% of super absorbent fiber LANSEAL (registered trademark) F sold by Toyobo Co., Ltd. and thermal adhesive polyester / polyethylene composite fiber A non-woven fabric having a thickness of 2 mm and a thickness of 185 g / m ² was prepared using (thermal adhesive fiber).

Fibers are weighed, mixed, carded and fluffed to obtain a textile fabric. Thereafter, the fabric can be consolidated by needle punching. The nonwoven fabric is finally consolidated by melting the shell of heat-adhesive fibers by heating (calendering) and fixing the nonwoven fabric in its final form.

Preparation of hydrocolloid elastomer material The hydrocolloid elastomer composition was prepared by mixing with a mixer.

The elastomer composition is expressed as follows in terms of% by weight based on the total weight of the composition.
Mineral oil sold under the trade name Ondina (registered trademark) 919 by Shell: 41.7%;
-Sodium salt of carboxymethyl cellulose (hydrocolloid) sold under the trade name CMC Blanose (registered trademark) 7H4XF by AQUALON: 14.8%;
Poly (styrene / ethylene / butylene / styrene) block copolymer sold under the trade name KRATON (registered trademark) G1651E by Kraton: 4.7%;
Antioxidant sold under the trade name IRGANOX® 1010 from Ciba Specialty Chemicals: 0.2%;
-Tackifying resin sold under the trade name ESCOREZ (registered trademark) 5380 by Exxon Chemicals: 35.6%;
2-methyl-2-[(1-oxo-2-propenyl) amino] -1-propanesulfonate and 2-hydroxyethyl propenoate sold under the trade name SEPINOV (registered trademark) EMT10 by SEPPIC Copolymer with ester: 5%.

Various components were added at 105 ° C. to 115 ° C. with stirring to obtain a homogeneous mixture.

More specifically, mineral oil, hydrocolloid and elastomer were first added, then antioxidant, SEPINOV® EMT10, and finally tackifying resin.

Coating of non-woven fabric using adhesive material The non-woven fabric was coated with this adhesive in the form of a mesh-like fabric having a basis weight of 180 g / m ² and a square mesh. Coating is performed by hot melt transfer using an etched cylinder. The width of the yarn is 1.6 mm. The surface area of the square opening is 4 mm ² . Covered 70% of the surface. The thickness of the thread of the adhesive material is 0.2 mm.

In vitro fibrin substrate removal test “Fibroblast migration in fibrin gel materials”, Arm J. et al. A fibrin substrate was prepared according to the Brown method described in Pathol, 1993, 142: 273-283.

The components and procedures used are as follows.
The following were dissolved at 37 ° C.
-5 ml of an aqueous solution containing 50 mmol of HEPES (Sigma-Aldrich catalog);
-Human plasma-derived fibrinogen 15 mg (Sigma-Aldrich catalog);
· CaCl ₂ 5mmol.

50 μl of human plasma-derived thrombin (100NIH) (Sigma-Aldrich catalog) was added to the solution thus prepared.

This mixture was placed in a petri dish and incubated at 37 ° C. for 24 hours.

After 24 hours, a fibrin substrate is formed. A sample of the dressing prepared as described above is placed on this substrate for 24 hours at room temperature.

Upon removal, it was observed that the fibrin separates from the support and is transferred as a lump to the surface of the removed dressing.

Comparative Examples 2-3:
Production of non-woven fabric Non- woven fabrics of Comparative Examples 2 to 3 are produced in the same manner as described in Example 1.

Composition of hydrocolloid elastomer material of Comparative Example 2 The elastomer composition of Comparative Example 2 was the same as that described in Example 1.

Composition of hydrocolloid elastomer material of Comparative Example 3 The elastomer composition is as follows in terms of% by weight based on the total weight of the composition.
Mineral oil sold under the trade name Ondina (registered trademark) 917 by Shell: 32.62%;
-Sodium salt (hydrocolloid) of carboxymethyl cellulose sold under the trade name CMC Blanose (registered trademark) 7H4XF by AQUALON: 30%;
Poly (styrene / ethylene / butylene / styrene) block copolymer sold by Kraton under the trade name KRATON® G1651E: 3.86%;
Antioxidant sold under the trade name IRGANOX (registered trademark) 1010 by Ciba Specialty Chemicals: 0.16%;
-Tackifying resin sold under the trade name ESCOREZ (registered trademark) 5380 by Exxon Chemicals: 25%;
-2-Methyl-2 [(1-oxo-2-propenyl) amino] -1-propanesulfonate and 2-hydroxyethyl ester of propenoic acid sold under the trade name SEPINOV (registered trademark) EMT10 from SEPPIC Copolymer with: 11%.

Preparation of hydrocolloid elastomeric materials of Comparative Examples 2-3 A hydrocolloid elastomeric material of Comparative Examples is prepared as described in Example 1.

Coating of non-woven fabric using adhesive material In Comparative Example 2, the non-woven fabric was coated with the above-mentioned adhesive material in the form of a mesh-like cloth having a basis weight of 662 g / m ² and a square mesh. The coating was performed by hot melt transfer using an etched cylinder. The thickness of the yarn was 0.84 mm.

In Comparative Example 3, the non-woven fabric was coated with the adhesive material in the form of a mesh-like cloth having a basis weight of 840 g / m ² and a square mesh. The coating was performed by hot melt transfer using an etched cylinder. The thickness of the yarn was 1 mm.

Absorption capacity measurement:
Absorption capacity was measured using a perforated glass plate with a diameter of 30 mm, and the hydrophobic foam / weight assembly was changed to a Plexiglas plate / weight applying a pressure of 40 mm mercury as a whole. The standard EN ISO 9073-12 for measuring the absorbent capacity of nonwovens was followed.

The liquid used was a NaCl / CaCl ₂ solution containing 298 g NaCl and 368 g CaCl ₂ per liter of water.

Absorption capacity results are expressed in grams in the table below.

The absorption amount of the coating material of Comparative Example 2 in which the basis weight of the hydrocolloid elastomer material exceeds 500 g / m ² is the same as that of Example 1 of the present invention at 1 hour or 24 hours even though the hydrocolloid content is the same. Much less than the dressing.

The absorption amount of the coating material of Comparative Example 3 in which the basis weight of the hydrocolloid elastomer material exceeds 500 g / m ² and the hydrocolloid amount exceeds 20% by weight is less than the coating material of Example 1 of the present invention in 24 hours. When the specific contact layer of Example 1 was used, it was found that, unlike the contact layer described in the counter example, the absorption rate of the nonwoven fabric was not lowered and this absorption capacity was maintained for a long time.

Claims (15)

a. An absorbent non-woven compress fabric comprising a mixture of superabsorbent conjugate fiber and heat-adhesive non-absorbent fiber, wherein the entire fiber is thermally bonded;
b. A dressing having a contact layer partially covering the surface of the compressive fabric that contacts the wound,
The layer has an opening through which wound exudate can pass, the basis weight of the layer is in the range of 110 to 500 g / m ² , and the layer is composed of a composition including an elastomer base material and a hydrocolloid, and contains hydrocolloid A dressing, the rate of which is 2% to 20% by weight of the composition. The covering material according to claim 1, wherein the heat-adhesive non-absorbable fiber is a composite fiber. The covering material according to claim 2, wherein the heat-adhesive non-absorbable fiber is a core / shell type composite fiber, the core is made of polyethylene terephthalate, and the shell is made of polyethylene. The superabsorbent fiber is a core / shell type composite fiber, the core is made of polyacrylonitrile, and the shell is made of polyacrylate. Coating material. 5. The covering material according to claim 1, wherein the basis weight of the pressing cloth is in a range of 40 to 400 g / m ² . The covering material according to any one of claims 1 to 5, wherein a thickness of the pressing cloth is in a range of 0.6 to 3 mm. The coating material according to any one of claims 1 to 6, wherein a weight ratio of the absorbent fiber and the heat-adhesive non-absorbable fiber is 60/40 to 80/20. The covering material according to claim 1, wherein the basis weight of the contact layer is in a range of 150 to 200 g / m ² . The contact layer covers 50% to 80%, preferably 65% to 75%, of the surface of the compressing cloth facing the wound before being exposed to wound exudate. The coating | covering material as described in any one of Claims 1-8. The contact layer is in the form of a mesh-like cloth made of yarn, characterized in that the thickness measured in a plane parallel to the surface of the maximum area is 1 to 3 mm, and the interval is 1 to 3 mm. The coating | covering material as described in any one of Claims 1-9. Wherein the surface area of the opening of the contact layer is 0.5 to 10 mm ^2, preferably 0.8~6mm ^2, dressing as claimed in any one of claims 1 to 10. The said hydrocolloid is selected from the alkali metal salt of carboxymethylcellulose, The coating | covering material as described in any one of Claims 1-11 characterized by the above-mentioned. The dressing according to any one of claims 1 to 12, wherein the hydrocolloid accounts for 8 to 18% by weight of the total weight of the composition. The dressing according to any one of claims 1 to 13, wherein the hydrocolloid accounts for 12 to 16% by weight of the total weight of the composition. 15. A dressing according to any one of the preceding claims, wherein the contact layer comprises an active agent that promotes wound healing or treatment.